Group B Strep: The Test Every Pregnant Woman Needs

The infection can cause health problems, even death, in infants

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HealthDay Reporter

(HealthDay is the new name for HealthScoutNews.)

THURSDAY, July 24, 2003 (HealthDayNews) -- For a pregnant woman, the test is simple and painless, but it can prevent a lifetime of grief and perhaps even save the life of her baby.

It's the test performed in late pregnancy for a bacterium called group B streptococcus, or GBS, which can threaten the life of a newborn if it is transmitted from mother to child. To detect it, the obstetrician simply swabs the vaginal and rectal area and sends the sample to the laboratory, where a culture is grown to determine if GBS is present.

While many women who have been pregnant before know about the test, those experiencing their first pregnancy often do not, says Dr. William Growdon, chairman of obstetrics and gynecology at Santa Monica-UCLA Medical Center in California.

"Usually at the beginning of the visit, I'll say, 'This is the time we need to be looking for a bacterium that is dangerous to your baby at the time of delivery,'" he says.

To focus attention on the problem, July has been designated International Group B Strep Awareness Month.

Awareness of the importance of testing for GBS is growing, says Dr. Charles Prober, a professor of pediatrics at Stanford University School of Medicine, and a member of the American Academy of Pediatrics' Committee on Infectious Diseases.

If left untreated in a woman about to give birth, Group B strep can be transmitted to the newborn. GBS is the most common cause of blood infection, or sepsis, in newborns, as well as infection of the lining and fluid around the brain, or meningitis, according to the U.S. Centers for Disease Control and Prevention (CDC).

Under revised CDC guidelines released in 2002, it's recommended that every pregnant woman be screened for GBS at 35 to 37 weeks of gestation. The American College of Obstetricians and Gynecologists also recommends that every pregnant women be tested.

Before the test was widely recommended, about 8,000 babies in the United States were afflicted annually with group B strep and one in 20 would die, according to the CDC. Those who survive often have long-term problems, including learning disabilities and vision problems.

Since testing has become more common, the incidence of group B strep in babies less than one week old has declined by more than 70 percent, the CDC says.

If the test comes back positive, preventing transmission is relatively simple -- the woman is given antibiotics beginning four to six hours before delivery, Growdon explains.

When you consider that between 10 percent and 30 percent of pregnant women are infected with the bacterium, Growdon says, it's crucial to be alert to the potential problem, since those affected often do not have symptoms.

Prevention techniques are good, but not perfect, Prober points out. "There are two types of GBS [in infants]," he says. "Early onset starts within five to seven days." Late onset, which could be contracted from the mother or from other people who carry the germ, shows up after five to seven days.

The typical treatment of GBS infections in newborns is also antibiotics, administered intravenously, according to the CDC.

About half of the late-onset GBS in newborns comes from their mother, the CDC estimates. The rest of the infections come from carriers of the bacterium, according to the March of Dimes.

Experts agree that getting the test done in late pregnancy is the best way to reduce a baby's risk.

More information

For more information on group B strep, visit the U.S. Centers for Disease Control and Prevention and Group B Strep Association.

SOURCES: William Growdon, M.D., chairman, obstetrics and gynecology, Santa Monica-UCLA Medical Center, Santa Monica, and clinical associate professor, obstetrics and gynecology, University of California, Los Angeles David Geffen School of Medicine, Los Angeles; Charles Prober, M.D., professor, pediatrics, Stanford University School of Medicine, Palo Alto, Calif.

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